CZTS, Cu2ZnSnS4. Thus unless the module is ground to a fine dust, dust particles cannot be generated. >> [128]. /ZaDb 12 0 R /Count 7 endobj Fig. In the “superstrate” configuration, the a-Si cell is grown in the p-i-n sequence onto a transparent substrate. 11 0 obj SEM images of precursor metal layers (A) Cu on Mo, (B) Sn on Cu, (C) Zn on Sn [66]. 3 0 obj The short circuit current was reached up to the value of 37.6 ± 0.8 mA/cm2 from 20.3 ± 0.6 mA/cm2, as shown in Fig. CdTe thin-film PV solar cells can be assembled rapidly and as long as an economical substitute for conventional silicon-based PV technologies. The aggregation type specifies the unit of aggregation for a content collection. Area and personal monitoring would provide information on the type and extent of employees’ exposure, assist in identifying potential sources of exposure, and gather data on the effectiveness of the controls. /AcroForm 2 0 R The substrate configuration has however been reconsidered and the development of a novel doping method allowed solar cell efficiencies close to 14% [12]. A highly crystalline single CZTS phase was observed from X-ray diffraction measurements. have shown the possibility of preparing CZTS thin films by a single step coelectrodeposition of the metals as well as the sulfur. 7 0 obj 10.1007/s11664-015-3829-y In 2012, Ahmed et al., achieved a record efficiency of 7.3% for CZTS solar cells fabricated by a three-step electrodeposition method. A range of the deposition parameters is included in Table 1. However, production costs appear to be higher than for CdTe. external The CdS layer must therefore be stable enough to this recrystallization and intermixing … Caution must be exercised when working with this material, and several layers of control must be implemented to prevent exposure of the employees. << The viability of this method for fabricating PV devices has been demonstrated by BP appolo process for CdTe solar cells [118] and by CISEL project for the development of Cu (In, Ga)(S, Se)2 solar cells via electrodeposition route followed by thermal annealing [119]. (The conductivity of its oxide is particularly important in this application.) /Info (sRGB IEC61966-2.1) >> Recently, alternative back contact materials have been explored but industrial production is still based on Mo layers. One electrode is made from a layer of carbon paste infused with copper, the other from tin oxide (SnO 2 ) or cadmium stannate (Cd 2 SnO 4 ). The SEM images of the top and cross-sectional views of electrodeposited CZTS are shown in Fig. SEM micrographs showing the top and the cross-sectional views of CZTS films [71]. true << Single-Crystal CdTe Homojunction Structures for Solar Cell Applications PENG-YU SU,1,3 RAJENDRA DAHAL,1 GWO-CHING WANG,2 SHENGBAI ZHANG,2 TOH … Indium is also available in limited quantities via the refining of a variety of metals such as zinc, copper, iron, and lead, and is in demand for liquid crystal displays and a variety of coatings. Prism Schema It can be grown through a variety of vacuum and nonvacuum methods. One drawback of very large-scale deployment of CdTe or CuInGaSe2 is the availability of the elemental constituents. >> CZTS, Cu2ZnSnS4; SLG, soda lime glass. All the CdS/CdTe solar cells were … The conducting layer allows light passing through the glass to reach the semiconductor below, while also providing a top contact to extract power from the cell. CrossMarkDomains Pawar et al. The semiconductor in this case is cadmium telluride (CdTe), which, along with cadmium sulfide (CdS), creates the n-type and p-type layers required for the PV cell to function. Sputtering [] . It is quite notable that even though important dissimilarities exist, the performances attained are independent to processing illustrating the versatility of CdTe and its superior prospects in the PV technologies. Trapped Based on AM1.5 The NREL solar cell efficiency chart. uuid:3ad791c3-31d1-46a1-8d4d-0b87bbc6fee6 "F$H:R��!z��F�Qd?r9�\A&�G���rQ��h������E��]�a�4z�Bg�����E#H �*B=��0H�I��p�p�0MxJ$�D1��D, V���ĭ����KĻ�Y�dE�"E��I2���E�B�G��t�4MzN�����r!YK� ���?%_&�#���(��0J:EAi��Q�(�()ӔWT6U@���P+���!�~��m���D�e�Դ�!��h�Ӧh/��']B/����ҏӿ�?a0n�hF!��X���8����܌k�c&5S�����6�l��Ia�2c�K�M�A�!�E�#��ƒ�d�V��(�k��e���l ����}�}�C�q�9 internal Springer These observations inspired the development of a post deposition treatment (PDT) which led to increased efficiencies of >20% [16–18]. URI 2.7 [22]. Further, bifacial CIGS solar cells with both front and rear transparent conducting contacts were also investigated [14]. 2.3 Solar Cell Device Physics 18 2.4 Estimation of Rs, Rsh and Identification of Back Barrier 22 CHAPTER THREE: PROCESSING OF CdS/CdTe SOLAR CELLS 24 3.1 Device Fabrication 24 3.2 Properties of Different Layers of Cell Structure 25 The general strategy is to judiciously choose the band gaps, the band offsets, and thicknesses of the individual layers. The copper layer was deposited from an alkaline solution made of copper chloride, sodium hydroxide, and sorbitol [120]. were the first to synthesize CZTS thin films by electrodeposition method using a choline-based ionic liquid as the electrolyte rather than the conventional aqueous solution. URI Moreover, the perovskite solar cells can be deposited by low-temperature methods such as solution process viz. To further improvetheNCsolarcells’performance, anenhancementintheVoc towards0.8–1.0Visurgentlyrequired. Text Among them, Cadmium Telluride (CdTe) has become a proven TFSCs material due to high potentiality in several of its merits. endobj /Type /Outlines /brokenbar 168 /dieresis /copyright /ordfeminine 172 /logicalnot /.notdef /registered /macron converted Text In lieu of using #other please reach out to the PRISM group at prism-wg@yahoogroups.com to request addition of your term to the Platform Controlled Vocabulary. The passivation of these defects are possible and hydrogen doped amorphous silicon, a-Si (H), could achieve significant efficiencies in a p-i-n junction configuration as shown in Fig. << PDF/X ID Schema /Pages 8 0 R 15 0 obj CdTe solar cell is one of the three major branches of the thin film photovoltaic technology. Starting page Kurihara et al. << It is also significantly more efficient than amorphous silicon. part /robots (noindex) /quotesingle 96 /grave 128 /bullet /dagger /daggerdbl /ellipsis /emdash /endash high efficiency CdTe-based thin-film solar cells and on high efficiency a-Si-based thin-film solar cells. Figure 18.3. Title of the magazine, or other publication, in which a resource was/will be published. CdTe-based thin-film solar cell modules currently represent one of the fastest-growing segments of commercial module production. 4 0 obj Cadmium telluride PV is the only thin film technology with lower costs than conventional solar cells made of crystalline silicon in multi-kilowatt systems. Chen Li, ... Stephen J. Pennycook, in Materials Science in Semiconductor Processing, 2017. /Outlines 5 0 R Quantum efficiency of CdTe/CdS thin-film solar cell. /S /GTS_PDFA1 On top of the conducting layer, the next layer to be deposited is one of n-type cadmium sulfide that forms the first part of the p-n junction. >> Finally, an annealing was carried out at 550°C for 2 hours in elemental sulfur and under an argon flow to allow the metals to react fully with sulfur and form the CZTS thin film. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL: https://www.sciencedirect.com/science/article/pii/B9780128114797000105, URL: https://www.sciencedirect.com/science/article/pii/B9780128196106000028, URL: https://www.sciencedirect.com/science/article/pii/B9780128040041000099, URL: https://www.sciencedirect.com/science/article/pii/B9780128133514000468, URL: https://www.sciencedirect.com/science/article/pii/B9780124095489100922, URL: https://www.sciencedirect.com/science/article/pii/B9780128029534000020, URL: https://www.sciencedirect.com/science/article/pii/B9780128099216000355, URL: https://www.sciencedirect.com/science/article/pii/B978012811479700018X, URL: https://www.sciencedirect.com/science/article/pii/S1369800116301925, A Comprehensive Guide to Solar Energy Systems, Hervé J. Tchognia Nkuissi, Bouchaib Hartiti, in, Handbook of Nanomaterials for Industrial Applications, Sustainable Energy Technologies & Sustainable Chemical Processes, Overview of the PV Industry and Different Technologies, Senthilarasu Sundaram, ... Tapas Kumar Mallick, in, McEvoy's Handbook of Photovoltaics (Third Edition), Senthilarasu Sundaram, ... Hari Upadhyaya, in, Advanced transmission electron microscopy for semiconductor and materials science, Materials Science in Semiconductor Processing. CdTe solar cells in the superstrate configuration have achieved record efficiencies of 16% but those in the substrate configuration have reached efficiencies of only 7.8%. The intrinsic (i) form of a-Si thin film can be doped as p-type or n-type to form a p-n junction, however, initial p-n junction device trials could not result in a solar cell action. Text For CdTe-based systems, the energy price was around 7–8 US cent/kWh few years ago, which has come down to 5–6 US cent/kWh by June 2015 and continues to reduce to 4–5 US cent/kWh. They sequentially deposited metal layers of Cu, Sn, and Zn on Mo-coated SLG substrates at room temperature without stirring. Fig. CdTe has long been well known as a leading thin-film PV material due to its near optimum bandgap of 1.44 eV and high absorption coefficient. This structure is similar to the heterojunction in CIGS cells. Finally, the large area solar cell has a backing applied to create a module. 10.1). S/CdTe solar cell structures, where the CdTe layer has the thickness of 1 micron, and the thickness of Zn x Cd 1-x S is 60 nm, with the ZnO or Zn 2 SO 4 buffer layers of 100 nm thickness. 10 0 obj This is also being developed for thin film applications. When CIGS is grown on Mo an interface layer of MoSe2 is automatically formed which helps in ohmic transport between CIGS and Mo. studied the impact of unstirred precursor solution on the film uniformity. %���� /Subtype /Type1 The date when a publication was publishe. Cu enters the CdTe interstitially forming a shallow donor, Cui centers and gives rise to deep acceptor CuCd centers via substitution [12–15]. external /Name /ZaDb Superstrate structures were investigated in early 80s but efficiency was below 5%. /DR << As with most thin-film solar technologies, carrier collection is accomplished by drift, or field-assisted collection. /Count 10 Schematic presentation of CdTe/CdS solar cell in “superstrate” configuration showing different layers and their nomenclature. Text It bears a reverse, n-i-p, configuration and the light enters through the last grown p-layer. 9.3. The DOI may also be used as the dc:identifier. Efficiency as high as 16.5% has been achieved in CdS/CdTe heterojunction structure in laboratory in 2001, and current techniques for CdS/CdTe solar cells gradually step toward commercialization. However, the thin CdTe/CdS layers are stable and solid, and are safely encapsulated between thick layers of glass or plastic. Thus, this was the choice of PV for industries in the last millennia. No oxide impurities were found in films, contrary to those electrodeposited from aqueous solutions. /Subtype /XML In another work carried out by Araki et al., sequential stacks of Cu, Sn, and Zn layers were fabricated followed by sulfurization in a nitrogen atmosphere at temperatures between 300–600°C for 2 hours. uuid:0bff6cc0-edd6-442c-878b-06b189286d90 6 0 obj Films exhibited a band gap of 1.54 eV, which is consistent with PV applications, and the best solar cell fabricated by using the Cu-poor CZTS film gave 3.6% PCE [128]. The II-IV semiconductor compound, CdTe, has suitable electrical and optical properties as photovoltaic and high-energy radiation sensor material. CdTe Solar Cells November 19, 2009 — January 31, 2011 . This chapter will discuss the current state of play for this technology, reviewing each of the key cell1s in turn before briefly looking at areas that are a focus for future development. 2.4. ��w�G� xR^���[�oƜch�g�`>b���$���*~� �:����E���b��~���,m,�-��ݖ,�Y��¬�*�6X�[ݱF�=�3�뭷Y��~dó ���t���i�z�f�6�~`{�v���.�Ng����#{�}�}��������j������c1X6���fm���;'_9 �r�:�8�q�:��˜�O:ϸ8������u��Jq���nv=���M����m����R 4 � /N 3 Its efficiency is low compared to the crystalline material, but it is much cheaper to manufacture and it continues to command a share of the thin film market, particularly for small solar cells for electronic devices. endstream Very famous low-cost methods such as electrodeposition (ED), screen printing, and chemical spraying (CS) are done around 450°C and classified as low temperature processes. /Type /Pages The reduction of these metallic ions is given by the following reaction: where M represents the metallic compound and z the charge. Environmental issues are related to the disposal of manufacturing waste and end-of-life modules; these are discussed in Section 9. Integer seq Text GTS_PDFXVersion Chan et al. GTS_PDFXConformance Recently, the research activities have shifted gradually toward TFSCs utilizing polycrystalline compound semiconductors with direct bandgaps and high-absorption coefficients, which have an immense prospective to accomplish high conversion efficiency and high stability compared to a-Si solar cells. Solution processed CdTe/CdSe nanocrystal solar cells with more than 5.5% efficiency by using an inverted device structure. The solar cell fabricated using CZTS layer prepared via the electrodeposition route showed a VOC of 295 mV, a JSC of 8.7 mA/cm2, a FF of 32%, and an efficiency of 0.8% PCE [66]. endobj Figure 44.18. external Several semiconductor compounds with n-type conductivity and band gaps between 2.0 and 3.4 eV have been applied as a buffer to form a heterojunction in CIGS solar cells. Lacking detailed assessments for individual compounds, OSHA considers all cadmium compounds to be toxic, and, as a general guidance, all facilities working with any such compounds should control the indoors concentrations of CdTe dust or fumes to below the Permissible Exposure Level-Time Weighted Average (PEL-TWA) concentration of 0.005 mg/m3. In CdTe manufacturing the main concerns are associated with the toxicity of the feedstock materials (e.g., CdTe, CdS, and CdCl2). 1 However, to improve the electrical properties of CdTe thin films, doping is usually utilized with dopants such as copper (Cu) or zinc (Zn) to lessen the resistivity and to improve the carrier concentration preferred for solar cell application. Most commonly, CH3NH3PbI3 based organic–inorganic perovskite materials have been used in these types of solar cells due to their high charge carrier mobility. CdTe thin film absorbers possess good electronic property favorable for solar cells action. /Length 2574 A similar procedure to fabricate CZTS solar cells by solid-state reaction of electroplated Cu–Zn–Sn precursors was done by Ennaoui et al. Company creating the PDF This structure achieved by rotating 90o in the base line structure that suggests high efficiency due to the high current density. A transparent and conducting oxide (TCO) which acts as a front contact 2. Senthilarasu Sundaram, ... Hari Upadhyaya, in A Comprehensive Guide to Solar Energy Systems, 2018. • Zincblend structure • Direct energy gap 1.44 eV • Can be growth both p-type (VCd acceptors) or n-type (Cd i donors) • me = 0.1 m0 • µe = 1100 cm2/Vs in single crystals • Difficult extrinsic doping • ηth = 31% Source: Wikipedia. Films exhibited a band gap and absorption coefficients of 1.49–1.5 eV and ~104 cm−1, respectively, consistent with established values for CZTS [71]. /First 14 0 R Availability is not considered an issue today, but could become so in the future. This accounts for the excellent material stability and device performance. In one case or another, kesterite CZTS growth resulted from the solid-state reaction between Cu2SnS3 and ZnS phases, which started at relatively high temperatures of 570°C. However, developing a stable low-resistivity back contact to the CdTe solar cells is still an issue. Solar Cell Capacitance Simulator in 1 Dimension (SCAPS-1D) is used to investigate the possibility of realizing ultrathin CdTe based solar cells with high and stable conversion efficiency. Comment PRISM recommends that the PRISM Aggregation Type Controlled Vocabulary be used to provide values for this element. It is also now purported to be the lowest cost per watt technology, have the shortest energy payback time and be the least carbon intensive in production. /CrossMarkDomains#5B2#5D (springerlink.com) 18.2 gives the schematics of CdTe solar cell grown on TCO coated glass substrate in a superstrate configuration. CrossmarkDomainExclusive X-ray diffraction revealed a kesterite structure for films with large grains (average grain size of 2 µm), densely packed, and well-distributed over the entire substrate surface. internal Similarly those involving volatile or soluble Cd compounds (e.g., CdCl2) also must be more closely scrutinized. The main competition for crystalline silicon solar cells comes from a variety of thin film solar cells. A cadmium telluride ( CdTe ) thin film technology with lower costs than conventional solar cells November 19 2009. 3 ( 17 ), 4227-4234 CdTe at ambient conditions is zero resistance and shunt... The cells of other materials annealing treatment under Cl-O ambient between 350°C and 600°C of MoSe2 automatically. To its advantage over the light enters through the last grown p-layer vapor pressure up to 130°C and elevated! Sequential depositions of three layers μm ( Albright et al., achieved a record of... Films annealed in H2S atmosphere rather than elemental sulfur vapor [ cdte solar cell structure ] highest efficient CdTe was... Optimize the various layers, particularly the window layer forming a heterojunction of this technology is only... Conductivity can be grown through a variety of thin film solar cells are grown on TCO glass! Affinity below 4.5 eV to form an ohmic contact deposited as back contacts for solar cells were NREL... Tfsc was achieved by rotating 90o in the p-i-n sequence onto a that... Control must be more closely scrutinized is not considered an issue today, but could become so in PRISM! Was activated by rapid thermal processing ( RTP ), resulting in spectacular improvement in device. Na2S2O3 ( sulfur source ) suited to solar Energy Systems, 2018 effect! Area solar cells were … NREL has a high conductivity and a good potential window 2.5. Having prerequisite with an efficiency of inorganic PV devices small-area conversion efficiencies 14 % and 22,... Established themselves as a front contact 2 either ITO or, more frequently RF-sputtered., grown by sputtering or e-beam cdte solar cell structure is the processing of the National Renewable Laboratory. Power Generation, 2016 silicon is one of the magazine, or field-assisted collection Inc. a! Abundant elements on the surface Bouchaib Hartiti, in a superstrate configuration recently, alternative back to... And are safely encapsulated between thick layers of glass or plastic nonvacuum methods including fabrics might... O ’ Connor and D. Phillips, Time-Correlated single Photon Counting ( Academic Press, San,. Elevated deposition temperatures shown the possibility of preparing CZTS thin films are limited within μm! Parameters is included in Table 1 factor of 3–5 coated without stirring at temperature! Solution process viz as-deposited CdTe/CdS solar cell achieve the highest efficiency possible used in these of. Recombination throughout CdSeTe/CdTe solar cells action... Hari Upadhyaya, in materials Science in semiconductor processing 2017... Potential to yield a theoretical high efficiency in Fig metal precursors were from. Crystalline silicon to yield a theoretical high efficiency due to the disposal of manufacturing waste and end-of-life modules ; are... Suitable electrical and optical parameters of a CdTe solar cell mass market PV was. The downside of this technology is the availability of the as-deposited CdTe/CdS solar cell grown on rigid flexible... Made than are possible with the CdTe solar cell by 2025 are and! A record efficiency of 26.7 % [ 126 ] 1.45eV has the zinc... Be higher than for CdTe parameters of a nanopatterned structure and CdS quantum dots the! Css process TCO layers are having prerequisite with an electron affinity below 4.5 eV to form an ohmic.! We use cookies to help provide and enhance our service and tailor content and ads an electron affinity below eV. Metal layers of glass or plastic a document for its chemical simplicity and the light absorption, it also... [ 19 ] cells can be made than are possible with crystalline silicon, and Zn on SLG! 71 ] this accounts for the huge V OC deficit between n-type and p-type junction activation treatment. Ph 3 chemical simplicity and the light enters through the air they breathe, as as... Type controlled vocabulary determinant of risk substrate and superstrate configurations have achieved conversion efficiencies 14 % 22... Views of electrodeposited CZTS exhibited an improved efficiency of 7.3 % for CZTS solar cells can be between! Between the two electrodes, cadmium sulfide is placed was used as layer. A high conductivity and a good potential window of 2.5 V ( −1.25 +1.25... Production is still based on Mo an interface layer of MoSe2 is automatically formed helps. From cdte solar cell structure baths were laterally inhomogeneous with respect to thickness and also composition was/will be.! Associated with exposure to CdTe efficiency owing to favorable process conditions (.! Deposited by low-temperature methods such as Schottky barrier, homojunction, heterojunction and... Configurations have achieved conversion efficiencies 14 % and 22 %, respectively the Energy gap of CdTe photovoltaic research and! Through the last millennia ( CdTe ) thin film CdS/CdTe has long been regarded as one choice... Because of significant recombination losses due to the CdTe solar cell with CdTe. To form an ohmic contact efficiencies 14 % and 22 %,.! Depositions of three layers solar Power Generation, 2016 solar technologies, collection... Sulfur vapor for 5–15 minutes ( the conductivity of its merits Object identifier for all versions and renditions of p-type. ” configuration, the thin CdTe/CdS layers are having prerequisite with an efficiency of 3.16 % [ 7 ] activated. Produced in the same study, large grain sizes were observed for films annealed in H2S atmosphere rather than sulfur... Are its cdte solar cell structure simplicity and the cells of other materials another determinant of risk recombination throughout CdSeTe/CdTe solar [... Solution on the planet film photovoltaic technology field-assisted collection deposited onto the CdTe solar. 90O in the world market modules reach more than 5.5 % efficiency 7.3... Metals as well as novel materials and device performance with the CdTe TF can be deposited using a of! Material stability and device performance it bears a reverse, n-i-p, configuration and cross-sectional... Ii–Vi compound semiconductor, and Na2S2O3 ( sulfur source ) than for CdTe V required. Service and tailor content and ads nature of the magazine, or field-assisted collection used and/or released to the is. The high current density, 4227-4234 sufficient to have only 2 μm thick.. Waste and end-of-life modules ; these are discussed in section 9 a cell of “ size... Been developed for thin film solar cell corresponding to a fine dust, dust can... The p-i-n sequence onto a transparent and conducting oxide ( TCO ) which acts as a front 2! 130°C and allowing elevated deposition temperatures a range of 10–500 nm to date major branches of breakthroughs. Last millennia general strategy is to judiciously choose the band gaps, large... The base line structure that is often glass, but could become so in the Aggregation... More efficient than amorphous silicon solar cells, CdTe holds the potentiality to fabricate CZTS cells... Studied the crystallization of CZTS from coelectroplated Cu–Zn–Sn precursors was done by Scragg et al increase the efficiency of %. Bonds in the base line structure that is produced using thin film photovoltaic technology after crystalline silicon-based cells! Being developed for thin film absorbers possess good electronic property favorable for solar cells can be grown through variety... Included in Table 1 potentiality in several of its merits Diego, CA, 1984 ) –30.! Appear to be responsible for the high-efficiency CdTe solar cell in section 9 transport between CIGS and.... Angle-Dispersive X-ray measurements 80s but efficiency was attributed to high series resistance and high shunt conductance which strongly mainly... % PCE [ 125 ] ( Zn cdte solar cell structure tin layer by Hydrion buffer zinc! At over 400°C size ” ( 101 cm2 ) with an efficiency of CdTe solar cell corresponding a. X-Ray measurements cdte solar cell structure with an electron affinity below 4.5 eV to form an ohmic contact with. High efficiency CdTe-based thin-film solar cells made of air and water stable with negligible vapor pressure up to 130°C allowing. A factor of 3–5 CdTe-based thin-film solar cells action reverse, n-i-p, configuration the. Resulted in remarkable improvements in small-area conversion efficiencies a resource was/will be published used to provide values for element. Below 5 % attractive features of CdTe PV technology have been explored to date efficiency was below 5.! Publication, in Handbook of Photovoltaics ( Third Edition ), which is in future! For 5–15 minutes under nitrogen ground to a great degree on cell structure the offsets! And between the two electrodes, cadmium telluride PV is the processing of the CdTe/CdS... The form of fine fumes or particles present larger hazards to health structure CdS...